The purpose of this test is to monitor the current draw from an injector whilst observing the primary ignition trace.
Connection for diagnostic work will vary dependent on application.
Technicians should whenever possible gain access to the test circuit without damage to seals and insulation. If this is not possible then make sure appropriate repairs are completed.
General connection advice
PicoScope offers a range of options within the test kits.
Dependent on difficulty of access, choose from:
Testing sensors and actuators (to include relevant circuit/connectors):
Note: This helpfile refers to a 10:1 attenuator. If you are using a 20:1 attenuator please adjust the Probe settings for the relevant channel. These settings can be found under the Channel Options button, then: Probe > 20:1 Attenuator.
This test involves measuring a potentially hazardous voltage.
Please ensure you follow manufacturers safety instructions and working practices and ensure the rated voltage for all accessories you are using meets or exceeds the expected voltage.
Use the Waveform Buffer, Zoom and Measuring tools to examine your waveform.
In this waveform we can observe the current drawn by the injector (shown in red) at the same time as monitoring the primary ignition trace (shown in blue).
The main reason for evaluating these two waveforms together is to identify the cause of a non-start situation or sudden loss of power, causing the engine to stop.
If the primary trace is absent, there will be no switching of the injectors as these two circuits are timed together while the loss of the injector current signifies that a fault has occurred within the injection circuit.
The frequency of the injection trace when compared to the primary signal will differ between sequential and simultaneous injection. Sequential having one pulse per 720, while simultaneous will predominantly have two. Some simultaneous systems do however have a single pulse, but these are in the minority.
Please see individual waveform topics:
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.
We know that our PicoScope users are clever and creative and we’d love to receive your ideas for improvement on this test. Click the Add comment button to leave your feedback.